Fix variant for lilygo_t8_esp32s2

Author: francisduvivier

boards.txt

@@ -807,7 +807,7 @@ lilygo_t8_esp32s2.build.bootloader_addr=0x1000
 lilygo_t8_esp32s2.build.target=esp32s2
 lilygo_t8_esp32s2.build.mcu=esp32s2
 lilygo_t8_esp32s2.build.core=esp32
-lilygo_t8_esp32s2.build.variant=esp32s2
+lilygo_t8_esp32s2.build.variant=lilygo_t8_esp32s2
 lilygo_t8_esp32s2.build.board=LILYGO_T8_ESP32S2
 
 lilygo_t8_esp32s2.build.cdc_on_boot=0